This invention deals with improved methods of treating defects in body vessels. It has use in patient trauma caused by a gunshot wound, stabbing, etc. or where the vessel (artery, vein, or other body passage) is perforated or disrupted. It is also particularly adapted but not limited to reconstruction of an abdominal aortic aneurysm.
Presently such aneurysms are surgically corrected by the re-section thereof with accompanying installation of a replacement graft. Generally this graft is of a Dacron material constructed in longitudinally expandible tubular form and is surgically connected between the remaining portion of the aorta and the left and right iliac arteries. Such procedure is in detail described in an article set forth on FIGS. 1 through 20, Pages 231 through 233 entitled "Resection of Abdominal Aortic Anerurysm" published in the Atlas of Surgical Operations, 4th ed. R. M. Zollinger and R. M. Zollinger, Jr.. Such procedure is time consuming, requires high skill and involves a significant amount of patient risk. Accordingly, it would be highly desirable to replace such technique with a simpler, less traumatic procedure which is, accordingly, the primary object of the present invention.
These and other objectives of the present invention are accomplished by the use of a wire alloy coil for having shape memory characteristics. The wire in non-coil form is positioned in the weakened vessel such that upon reformation by an increase in temperature to the coil form enables the coil to bridge the weakened vessel portion so as to form a substitute vessel wall portion in that defective area. More specifically, the process involves a reduced or non-surgical restoration of the patency of a hollow body vessel which includes a localized defect disposed intermediate first and second potent vessel portions, comprising inserting at least the front end of a continuous length of shape-memory alloy wire which has been previously fabricated in its parent phase to form a longitudinally oriented coil of adjacent wire loops and then cooled to its martensite phase and reshaped to a relatively straight length along the interior of said vessel past said defect to a position adjacent the first potent vessel portion while maintaining the temperature of said wire below its martensite transformation point and thereafter heating said wire to its transformation point progressively from the front thereof to the rear thereof so as to initially cause the thus reshaped wire loops of the front wire end to be urged against the interior of said first potent vessel portion so as to be at least temporarily positioned thereat and thereafter cause the reformation of the remainder of said coil so as to bridge said localized defect and into position adjacent said second potent vessel portion.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawing.